Cooling Season Can Burn up Your Cash

"Yes! It's FINALLY getting warm out!"  This was my first thought, as well as the first thing out of my mouth, when I checked the forecast for today.  I am completely over cold weather, and I have a feeling I am not alone in that sentiment.  I am looking forward to walking the dog in the mornings and not being chilled to the bone, sitting outside in the evenings, and enjoying the beautiful sunsets from Libby Hill.  Point being-I am looking forward to the warm weather.  While I will take a stab in the dark and say many of you are as well, I will say your buildings, mechanical systems, and bottom lines are probably not sharing that elation.  Throughout this post we will take a look at why, and some of the steps that can be taken to make sure the warm weather keeps our spirits, and profits, up.

Commercial HVAC systems come in all shapes, sizes, designs, and applications.  However, they share similar features and equipment needed for the heating, cooling, and ventilation demands of the building.  It is important to understand they type of equipment that your facility relies on, but it is not necessary for you to know exactly how everything works together-that is why HVAC contractors and technicians exist.  I would like to educate you on one specific, and very important, aspect of your system: the coils.  The coils are the heat exchangers of the cycle providing the cool or warm conditions felt in the space.  On a basic knowledge level, there are condenser coils and evaporator coils.  When I began to learn about the workings of HVAC systems, the following schematic helped give me a basic understanding of what these pieces of equipment did. 

As the drawing indicates (it is a very basic visual of the cycle that only displays the function of each coil, not all parts of the cycle) the evaporator coil inside supplies the space with coil air while the condenser coil outside rejects the heat from the system.  Think of your home A/C system.  Many people have a condensing unit or two outside of the house somewhere.  When you hear that fan come on, the condenser is rejecting the heat, and condensing the refrigerant vapor to a cooled liquid state before sending it back through the system.  While commercial equipment is much more complex, the basic theory of operation still remains the same. 

 



 Now that we got the technical jargon out of the way, let's start to make "cents" of all of this (sorry, I had to).  You can imagine that equipment this focal in the heating and cooling process get its fair share of wear and tear.  Being outside, the condensing coils are subjected to weather, dirt, debris, among other elements.  This can produce a build up that inhibits the ability of the coil to transfer heat, making the system work harder to meet demand.  Think about going out for a long run in August, the heat and humidity at a peak.  Your body works harder than normal to maintain your core temperature, rejecting "heat" from your skin in the form of sweat.  Now picture going out for that same run while wearing a winter coat, long pants, and a gas mask.  Your body goes into overdrive trying to meet the demand you need to be comfortable.  However, it simply cannot keep up and you put your health in danger (do not attempt this, just visualize).  The same thing goes for your HVAC system.  When the coils are not cleaned they are essentially running with a gas mask on, reducing efficiency, increasing costs, increasing the likelihood of breakdown, and decreasing comfort conditions inside.

ASHRAE (American Society of Heating, Refrigeration, and Air-Conditioning Engineers) conducted a study on the financial benefits of cleaning coils.  The article that shares the research and findings is called Study Verifies Coil Cleaning Saves Energy. As always, a link to the article is available at the conclusion of the post.  The title does not leave any mystery as to what the results of the study are.  However, since I realize many people need to see the backup for such a claim, I will give you the hard facts.  One of the first paragraphs in the article really hammer home the importance of proper coil maintenance, and sets the stage for the rest of the article.

"We believe we found a methodology and regimen that proves maintaining air handler components in a clean condition can save energy dollars and improve other building parameter changes and efficiencies such as improved dehumidification and comfort, along with less mold and bacteria.  Thus, we are encouraging IAQ environmental parameter improvements, better tenant satisfaction, and increased worker effectiveness"

 

The study was performed at a 34-story building in Times Square, New York and was conducted by essentially measuring performance of air handlers before and after coil cleaning.  Some of the findings from the research are as follows:

• Improvements that will lead to energy savings of up to $40,000 in the year of the study
• Increased thermal efficiency of coil by 25% with respect to ability to transfer its energy to its sensible loads
• Increased thermal efficiency of coil by 10% with respect to ability to transfer energy to its latent loads
• Good maintenance and operation practices can significantly improve energy efficiency and IAQ performance of HVAC systems in a building by 10%-15%

I'd like to share with you two photos before wrapping up this post.  The first photo below is what a clean condenser coil looks like.

 

 

This coil does show some signs of wear, but is overall clean and operating efficiently.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The coil to the right is extremely dirty and will not be operating efficiently. 

 

 

 

 

 

 

 

 

 

 

 

 

To conclude, I hope the data and pictures speak for themselves.  A unit that is maintained properly is a unit that operates efficiently, and a unit that operates efficiently is one that operates at a reduced cost. With cooling season approaching quickly, make sure you building's "winter coat" so that it can breath and enjoy the warmth as well.

 

link to article: http://www.steril-aire.com/images/saveenergy.pdf

 

-Luke